The influence of porosity on machinability of sintered fe foam elements

The aim of the experiment was to study the machinability of porous metal foams formed by reduction of metal oxides during sintering. The analysis focused on the machining process of metal foams with respect to their porosity and mechanical properties. The factors investigated included the geometry of the specimens, the surface condition depending on the machining parameters (milling) and the porosity of the metal foam. The metallic porous structure was obtained as a result of sintering the mixture of iron based powders ASC 100.29 and DISTALOY SE (DIST SE) with porosity from 67,9 % (SE 1) to 77,8 % (SE 2) for ASC base powder and 75,7 % to 80.3 % for DISTALOY SE were used

STUDY TOWARDS THE TIME-BASED MCDA RANKING ANALYSIS – A SUPPLIER SELECTION CASE STUDY

Decision-making processes increasingly use models based on various methods to ensure professional analysis and evaluation of the considered alternatives. However, the abundance of these methods makes it difficult to choose the proper method to solve a given problem. Also, it is worth noting whether different results can be obtained using different methods within a single decision problem. In this paper, we used three selected Multi-Criteria Decision Analysis (MCDA) methods called COMET, TOPSIS, and SPOTIS in order to examine how the obtained rankings vary. The selection of material suppliers was taken into consideration. The equal weights, entropy and standard deviation methods were used to determine the weights for criteria. Final preferences values were then compared with the WS similarity coefficient and weighted Spearman correlation coefficient to check the similarity of the received rankings. It was noticed that in the given problem, all of the methods provide highly correlated results, and the obtained positional rankings are not significantly different. However, practical conclusions indicate the need to look for improved solutions in the correct and accurate assessment of suppliers in a given period

Selected properties of high velocity oxy liquid fuel (HVOLF) - sprayed nanocrystalline WC-CO INFRALLOYTM S7412 coatings modified by high energy electric pulse

The paper presents a brief study of selected properties of HVOLF-sprayed nanocrystalline WC-Co InfralloyTM S7412 coatings modified by the application of a high energy electric pulse. The anti-wear coatings were applied on carbon steel with the use of High Velocity Oxy Liquid Fuel (HVOLF) spraying system TAFA – JP-5000. The process was modified by the application of the SST France & Vision Lasertechnik device WS 7000 S. The resultant type of coatings may be applied to increase the abrasive wear resistance of tools and machine parts. The properties of the powders and coatings were studied using metallographic methods and EDS analyses. The microhardness and nanohardness of the resultant layers were measured and Young’s modulus of elasticity was determined

Computed Tomography and Scanning Electron Microscopy Analysis of a Friction Stir Welded Al-Cu Joint

The study aimed touse3D computed tomography (CT) to analyse a joint between two dissimilar materials produced by friction stir welding (FSW). As the materials joined, i.e., aluminum and copper, differ in properties (e.g., density and melting point), the weld is predicted to have an inhomogeneous microstructure. The investigations involved applying microfocus computed tomography (micro-CT) to visualize and analyze the volumetric structure of the joint. Volume rendering is extremely useful because, unlike computer modelling, which requires many simplifications, it helps create highly accurate representations of objects. Image segmentation into regions was performed through global gray-scale thresholding. The analysis also included elemental mapping of the weld cross-sections using scanning electron microscopy (SEM) and examination of its surface morphology by means of optical microscopy (OP). The joint finds its use in developing elements used in the chemical, energetics and aerospace industries, due to the excellent possibilities of combining many different properties, and above all, reducing the weight of the structure

Sztuka umiaru. Wizje dewzrostowych instytucji sztuki

The aim of this article is to indicate and consider the propositions of reforming art institutions formulated by artists, which are close to the spirit and values of degrowth theories and practices. We claim that art and culture can play an important role in the posited degrowth transformation of the society, serving as tools providing the language, narratives, images, and imagination that support abandoning the dominating growth paradigm. As we show in the text, artists from Western Europe and the USA have been proposing to transform art institutions in the spirit of degrowth at least since the 1960s and 1970s. Many of them postulate that the institutions should abandon the voracious art consumption and production as well as rivalry in favor of developing sensitivity and social relations, escaping commodification and museification as well as ecologizing the imagination. In this article, we consider three models of such an institutional transformation: giving up the production of art, care work and reclaiming play and disposable time. We refer to a number of historical and contemporary art practices to show how each of the models implements the postulates of degrowth theories and practices, becomes a carrier of the values related to the culture of re-straint. We also discuss the different visions regarding degrowth galleries and museums of the future implied by each model. In the face of the contemporary tangle of crises, and especially the climate crisis, reforming art institutions in the spirit of degrowth seems necessary and the models we have considered should not be treated as metaphors but rather exercises in adapting to the changing con-ditions of living on Earth.Celem niniejszego artykułu jest wskazanie i omówienie formułowanych przez artystki i artystów propozycji reformy instytucji sztuki w duchu wartości bliskich teoriom i praktykom dewzrostowym. Twierdzimy, że sztuka i kulturą mogą pełnić istotną rolę w dewzrostowej transformacji społecznej jako narzędzia dostarczające języka, narracji, obrazów i wyobraźni wspierających dążenia do odejścia od dominującego paradygmatu wzrostu. Jak pokazujemy, artystki i artyści z Europy Zachodniej i USA co najmniej od przełomu lat sześćdziesiątych i siedemdziesiątych proponują reformy instytucji sztuki w duchu dewzrostowym: postulują odejście od zachłannej produkcji i konsumpcji sztuki oraz rywalizacji na rzecz rozwijania wrażliwości i relacji społecznych, ucieczki od utowarowienia i muzeifikacji oraz ekologizowania wyobraźni. W artykule omawiamy trzy modele tego rodzaju transformacji instytucji: zaniechanie produkcji sztuki, pracę opieki oraz odzyskiwanie zabawy i czasu wolnego. Powołując się na przykłady historycznych i współczesnych działań artystycznych, wskazujemy w jaki sposób każdy z modeli realizuje postulaty dewzrostu, jak staje się nośnikiem wartości kultury umiaru oraz jaką wizję dewzrostowych muzeów i galerii przyszłości wyraża. W obliczu splotu kryzysów współczesności, w tym szczególnie kryzysu klimatycznego, reforma instytucji sztuki w duchu dewzrostu wydaje się konieczna, a omówione przez nas artystyczne propozycje należy traktować nie jako metafory, lecz ćwiczenia z przystosowywania się do zmieniających się warunków życia na Ziemi

Less is enough. Culture of moderation in conceptual plein-air convention of the 1970s in Poland

The aim of this text is to analyse the conceptual plein-air convention of the 1970s as an example of practising moderation in the history of Polish culture. Conceptual plein-air meetings are shown as a great example of moderate artistic activity as well as an inspiration for creating and developing the idea of a moderate and good life in the present times. The first section of the article places the latter in the context of a broader debate on the climate crisis while calling for degrowth and moderation. The second part presents the artistic and social context of conceptual plein-air convention, highlighting the links between the limits to growth, criticism of development and technical advancement, and conceptual art. The third section analyses conceptual plein-air convention as a scenario for reflection on moderation and its practising in artistic creation. It also discusses the relevant – moderate – aspects of the 1971 Plein-Air Convention in the Zgorzelec Land and the 1972 Plein-Air Convention in Osieki, Poland. The authors conclude by emphasising the usability of the conceptual plein-air model as a tool for learning and practising the culture of moderation in modern times

Evolution of Russian assault-breaching subunit

In the Russian military art, the effectiveness of combat operations is largely dependent on the capabilities of the military engineering. It can be assumed that the capabilities of engineering forces are one of the major determinants of the efficiency of military operations. Taking into account the assumptions of contemporary operational art and tactics, the military engineering forces are constantly evolving, which results in their adaptation to the changing requirements of the environment of the operations being carried out. In this light, urbanized areas, including large agglomerations, are supposed to be places where engineering tasks will be executed. Based on the experiences of modern armed conflicts, Russian military engineers are primarily prepared for actions in the built-up environment. In the opinion of Russian specialists, the implementation of tasks in urban agglomerations requires the involvement of subunits, which ensure the maintenance of maneuverability, thereby increasing the effectiveness of combat measures used. One of the preferred solutions is to form, mainly on the basis of engineering troops, specialist task forces as assault-breaching subunits. Such an approach to adjusting (modernizing) the Russian Federation’s military engineering forces to the requirements of modern warfare is not revolutionary, but a permanent evolutionary process